I've never attempted to get a backpacking permit in Yosemite before, but what I've seen so far during my research makes me doubt the viability of showing up to get a first-come first-serve permit to go to Waterwheel Falls from Glen Aulin. I know the permit office at Tuolumne Meadows opens at 11AM, but how early should I be there to guarantee a permit? Or at least increase my chances? I'm hoping to go in late July, which I imagine is the most popular time to be up there

Wilderness permits are available during business hours at any permit issuing station beginning at 11 am the day before the beginning of your wilderness trip. Priority for permits for a particular trailhead is given to the closest permit issuing station, though it is possible to obtain a permit for any trailhead at any permit issuing station. This mainly affects the most popular trailheads that fill up quickly each morning, such as Little Yosemite Valley trailheads, Lyell Canyon, Cathedral Lakes, among others.

Here is the order of things: Most people try to reserve particularly coming from any great distance. A great number of those will never show up at the park to get their permit. They can't get a refund so they often don't bother to cancel. Therefore, the park is able to give those away - so they do that on the day that permit starts, at 10 am.

No, the Tuolumne Wilderness office does not open at 11. It opens at 8 am or 9 am depending on time of year. You only start getting those walk up permits that were not reservable at 11.

Therefore: You go the DAY BEFORE your anticipated start date, but be ready to start hiking. Get there at the wilderness office with priority over the desired trailhead at, oh, let's say 7-8 am, and hang out til 10 when they give away those reserved but abandoned permits. Get one and you start walking from the trailhead on your permit, after whatever shuttle or drive needed to get to that trailhead. No luck? Wait til 11 am and get one for the following day if you're lucky. No luck? If you showed up by bus or on a bike or on foot (hitchhiking counts as on foot) the superintendant's compendium says you can stay in the backpacker camp without a permit because you arrived by public transportation. Come back the following morning and start again. Wait til 10 to get an abandoned permit. Try again for a walk up for the next day at 11. If you do get a walk up, go for a day hike, stay in the backpacker camp for that night before with the permit, and go backpacking on schedule.

You can make your chances at a walk in increase by showing up midweek instead of Friday-Saturday-Sunday. Also being only a single hiker helps a ton.

I had a great couple of weeks in the area one summer -- I went with friends over Mono-Parker Pass on their permit, then stayed the night in the backpacker camp after the trip with that permit after everyone left. Got up and went to the wilderness office, snapped up a permit for Grand Canyon of the Tuolumne, drove to White Wolf and stayed in the backpacker camp there. Was drinking coffee on the porch at the restaurant when my friend showed up and gave me a ride back to Tuolumne Meadows, we started hiking, three days later I was back at my car at White Wolf. Drove back to the wilderness office, walked in, got another permit, stayed in the backpacker camp again, went out for another couple days. The store at Tuolumne Meadows has groceries and a hiker box that the thru hikers dump stuff in, and the permits are free.

nicely done, AT. And for a single hiker, it's amazing how many permits can find room on a trailhead quota. A group of six is a whole 'nother question, but we've seen people shoe=horned into a trail even thought the trailhead quota was "full" by an understanding ranger.

I've been backpacking in Yosemite for decades, and of at least several trips per year, I've only reserved a permit maybe twice, but never failed to go where I wanted, including Glen Aulin pass-through, the JMT, Sunrise...It's as AT says; it's strategically planning my arrival and knowing the drill, a workaround every once in awhile, and maybe with just a little luck thrown in. And aside from reservations and cancellations, even with walk-up permits, those unreservable quotas are still 40% of the spaces available at any given time, especially if you're good with picking up that permit the day before the hike. As a matter of fact, I find it infinitely harder to get a reservation than to just show up and go from there.

Another thing you can do is study up a bit before you go. Often there are alternative entry points that will allow you to do a similar hike. For example, heading to Glen Aulin from Murphy Creek is only ~1.5 miles further and perhaps slightly more from May Lake. If you have a couple of alternative hikes already in mind, you'll have a great chance of getting something interesting, having the right maps and a route plan in hand, and not having to scramble to adjust.